1. Field of the Invention
In general, the present invention relates to toy bow and arrow systems, where a toy bow is used to launch a toy arrow projectile into flight.
2. Prior Art Description
Bow and arrow sets that are designed for children's play have existed throughout recorded history. In the modern era, toy bow and arrow sets typically have a plastic molded bow, a string and safety-tipped arrows. To ensure safety, the functional design of a toy bow is also commonly altered. In a real bow, the string has a fixed length. The spring force used to launch an arrow comes from the flexing of the arms of the bow. The problem with this design is its failure mode. If a bow is drawn beyond its limit, then the arms or the string of the bow may break. Depending upon where the breakage occurs, the broken string and/or bow may fly toward the person holding the bow as the stored energy is accidentally released.
To reduce the likelihood of this hazard from occurring, many toy bows are manufactured as static structures. An elastic string is used to create the arrow launching force. If such a bow is overdrawn, there is no significant chance of the bow breaking. Rather, the elastic string will break and will most likely move in a direction away from the person drawing the bow. The failure mode of a string breaking is far less dangerous than the failure mode of the bow breaking. However, the failure mode of a broken string does present some danger depending upon where the elastic string breaks and how much energy is stored in the elastic string at the time it breaks.
Toy bows that use a static bow and an elastic string are exemplified by U.S. Pat. No. 5,247,920 to Harbin, entitled Toy Bow; and U.S. Pat. No. 7,748,369 to Chee, entitled Launching Apparatus and Assembly.
Many toy bows that have elastic strings use elastic strings that are made from a synthetic polymer, such as silicon, TPR or some other synthetic rubber. On the toy, such elastic strings are constantly under tension. As such, if the material of the string creeps or degrades, the elastic string will break. This stops the toy bow from being functional.
Most all plastic degrades in some fashion over time. However, it has been found that one of the fastest ways to degrade the preferred polymers used for the bowstring is to expose the bowstring to UV light. A bowstring that can last for months inside a home may only last for a few days if taken outside and left in sunlight. A toy that lasts for months is acceptable. A toy that last for days is not. Damage caused by exposure to light has therefore caused products to be returned and/or consumer's dissatisfaction with the toy manufacturer.
A need therefore exists for a toy bow and arrow design that inhibits degradation in the elastic string caused by exposure to light. This need is met by the present invention as described and claimed below.